Main Disconnecting Device [Q1.1] - ABB ACS880-37 Hardware Manual

Main disconnecting device [Q1.1]

Depending on the configuration of the drive, the main disconnecting device of the drive is
either a switch-disconnector or a main circuit breaker. Units with a switch-disconnector
also have a main contactor.
The main disconnecting device switches the main supply to the drive on and off. To
disconnect the main supply, turn the switch-disconnector to the 0 (OFF) position, or rack
out the main breaker (whichever device is installed).
WARNING! The main disconnecting device does not isolate the input power
terminals, AC voltage meters, or the *auxiliary voltage circuit from the power line.
To isolate the auxiliary voltage circuit, open the auxiliary voltage switch (Q21). To
isolate the input power terminals and AC voltage meters, open the main breaker of the
supply transformer.
*With frame 1×R8i + 1×R8i units, the main switch-disconnector [Q1.1] also switches the auxiliary voltage on
and off.
To close the main disconnecting device, auxiliary voltage must be switched on, and the
grounding switch (if present) must be open.
Auxiliary voltage switch [Q21]
The auxiliary voltage switch controls the supply to the auxiliary voltage transformers. The
transformer feeds the control circuits inside the drive such as cooling fans, relays and
measuring equipment. The switch is fitted with fuses.
Note: Frame 1×R8i + 1×R8i units are not fitted with an auxiliary voltage switch. The
auxiliary voltage is switched on and off by the main disconnecting device [Q1], and
protected by fuse disconnectors F20.1...F20.3.
Grounding (earthing) switch [Q9.x], optional
The grounding switch [Q9.1] (option +F259) connects the main AC power bus to the PE
busbar.
To close the grounding switch, auxiliary voltage must be switched on, and the main
disconnecting device must be open.
WARNING! The grounding switch does not ground the input power terminals of
the drive or the auxiliary (control) voltage circuits.
Other devices on the door
•
Voltmeter (option +G334); comes with a phase selector switch. Note: The voltage is
measured on the supply side of the main switch or breaker.
•
AC current meter (option +G335) on one phase.
Operation principle and hardware description 45